The Christmas flood of 1964 actually started several days before Dec. 25, and lasted many days after. Buckets of rain melted the snow on the ground, wiping out homes, livestock and people throughout the Pacific Northwest and northern California.

The Mount Hood corridor was among the hardest hit.

The U.S. Army Corps of Engineers called it the kind of flood that happens once in 100 years, but Clackamas County is taking the 50th anniversary to educate residents about what to do if it happens sooner than another 50 years.

Jay Wilson, the county's hazard mitigation coordinator, wants photos, videos and memories of the 1964 flood. He plans to use these artifacts of the biggest flood in most people's memory to personalize the event.

From researching Corps of Engineers and U.S. Geological Survey materials, Wilson said Clackamas County bore some of the worst damage at the time.

He wants to launch a campaign with online videos, town halls and other events to educate county residents about flood insurance and safety.

"We want to build on this anniversary as a remembrance that this can happen before, and can happen again," Wilson said.

The 1964 flood wiped out 155 homes in Clackamas County, Wilson said. Forty of those were in the Brightwood area -- mostly summer homes and cabins. When the waters receded, the flood left little to no evidence the houses stood there days before.

Wilson pointed out that the Brightwood area grew since then, and a huge flood would could reak even more damage.

"The Willamette River rose so high that the Willamette Falls turned into rapids, Oregon City was covered in several feet of water and homes, cabins, bridges and roadways were washed away by the Zig Zag and Sandy rivers on Mt. Hood," said county spokeswoman Ellen Rogalin.

Floods hit Clackamas County regularly -- 1996 neared the destruction of 1964. In 2011, the upper Sandy River flooded, and the county is still working with people in that area to prepare for the next time.

Many people think that flood mitigation looks like it did in 1964, when the Corps of Engineers bulldozed around the river to fix it, Wilson said.

"It built a lot of false assurances for people that you could basically come in and engineer a problem and basically destroy an ecosystem," Wilson said.

Now, he and the Emergency Management Department staff are teaching people to live with the river, instead of trying to control it.

If you have photos, film reel or any other "those kinds of things you can't find online or go to the library and find" from the 1964 flood, call Wilson at 503-723-484, or email him at jaywilson@clackamas.us.

The Oregonian unearthed some archive photos of Clackamas County from that time in the gallery above.